Enhanced photovoltaic efficiency of perovskite solar cell through reduced graphene oxide passivation

Photovoltaic response is substantially very crucial in perovskite solar cells, and it could be enhanced via grain boundary passivation. Here, reduced graphene oxide synthesized using the improved Hummers’ method was incorporated into the organic–inorganic methylammonium lead triiodide (CH3NH3PbI3) perovskite film and the bilayer electron transporting layer of CH3NH3PbI3-based PSCs. Characterization studies were carried out to examine structural, morphological, and optical properties by means of Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, and ultraviolet–visible spectrophotometry. The characterization studies showed intensity in absorption peaks, enhanced morphology, improved particle size (3.37–5.29 nm), redshift in absorption edge, energy bandgap reduction (1.90–1.72 eV), and reflectivity attenuation with rGO inclusion into CH3NH3PbI3 film. IV characteristics showed improved performance parameters (19.90–14.95 mA cm−2, 0.81–0.85 V, 58.61%–61.58%, and 5.52%–7.82% for Jsc, Voc, FF, and PCE, respectively). The percentage enhancement values of 7.00%, 4.71%, 5.26%, and 29.41% were also determined for Jsc, Voc, FF, and PCE, respectively. The study demonstrates that the synthesized rGO tremendously impacts the characteristics of the CH3NH3PbI3 film and the photovoltaic response of the ITO/TiO2/CH3NH3PbI3/graphite device.